Im Still waiting for the Retrobit Supa Retro Boy, but as EvilDragon currently got issues whit Nintendo because some of the Older Retro Bit Controllers looks like Nintendo Controllers, i ditnt think this will get released the next few months..
Got me a Original Game Boy Color some months ago, and i use a DS Lite for DS and GBA Games (and some GB GBC via the Emu Feature of the Everdrive GBA)..
The Gameboy wasnt the best Handheld, in therms of Ergonomic, but its the Handheld everyone remember..

Yes, it's basically a RetroPi - just with a custom board, that I think is more akin to the OrangePi

There's nothing stopping you connecting PSone controller into the USB ports at the top, though it does mean carrying extra hardware.
Still, if you're happy with SNES/Megadrive generation and lower - this should be cover pretty much everything you'd want.

Back button configuration is very likely to change (lot of people just complained about it!) I posted new design on "Update 1" of the Kickstarter to ask backers to vote and lot of people vote for new design. New design is this one :

There was also an analogue stick before the dual shock (which as the name suggests, added rumble). It's somewhat rare these days though.

I quite like the robust look of this with it's stone finish and chiselled edges. I dunno about it being analogue out to that LCD though - while there's some weird aliasing going on on that first game shown in the sky, that LCD connector on the PCB I would have assumed is a digital connector. And yeah, the price is about twice what I'd like to play for a knockabout console like this.

Enh, I'm burned out on GameBoy form-factor retro-gaming-puters. Its fun for a while but eventually I get tired of it.

The Pandora has life beyond being an RGP by virtue of the keyboard and pocket-ability. Mine has been awesome as a tool for playing around with python on the ride to work. I like that they tout this one as having desktop functionality, its a good angle.